It appears to me that the 'Allow everyone to vote' capability is coded backwards.
In the distribution the inc_func_common.asp modification starting in line 107 is:
if strWhoVotes = "members" then '### Members Only Mode
'## Insert vote into POLL_VOTES table
'############# Poll Mod Update 2.0.4 -> 2.0.5 ############
' Change strMemberTablePrefix -> strTablePrefix
strSql = "INSERT INTO " & strTablePrefix & "POLL_VOTES (GUEST_VOTE, MEMBER_ID, TOPIC_ID, FORUM_ID, CAT_ID)" & _
"VALUES (" & pGuest_Vote & ", " & pMember_ID & ", " & pTopic_ID & ", " & pForum_ID & ", " & pCat_ID & ")"
'#####################
'#########################################################
my_Conn.Execute (strSql),,adCmdText + adExecuteNoRecords
'############# Poll Mod Update 2.0.3 -> 2.0.4 ############
else '### Everyone Can Vote Mode
'#########################################################
if mlev > 0 then
'## Insert vote into POLL_VOTES table
'############# Poll Mod Update 2.0.4 -> 2.0.5 ############
'Change strMemberTablePrefix -> strTablePrefix
strSql = "INSERT INTO " & strTablePrefix & "POLL_VOTES (GUEST_VOTE, MEMBER_ID, TOPIC_ID, FORUM_ID, CAT_ID)" & _
"VALUES (" & pGuest_Vote & ", " & pMember_ID & ", " & pTopic_ID & ", " & pForum_ID & ", " & pCat_ID & ")"
'#########################################################
This coding does NOT record guest votes.
The first 'If' should be changed to:
if strWhoVotes = "everyone" then '### Everyone can vote
The 'else' line comment should be changed to:
else '### Members only can Vote